Elastase is a decomposing enzyme for the water-soluble scleroprotein, elastin, and has been found to directly act on living body to normalize serum lipid level and increase elasticity of blood vessel. In particular, it is known that serum elastase level is low in patients suffering from arteriosclerosis and aged people and, in this point of view, elastase has recently attracted rapidly increasing attention as a medicine for arteriosclerosis and hyperlipemia.
However, absorption of elastase through intestine is extremely poor, because it is a polypeptide having a molecular weight of 25,900. For example, it is reported that, when 1 mg and 5 mg of .sup.131 I-elastase dissolved in a physiological saline solution were administered intraintestinally to rats, it was absorbed only 0.15% and 0.05%, respectively, even summing the amounts absorbed through blood vessel route and those through lymphatic vessel route. [Biochim. Biophys. Acta. 288 (1972), pp. 181-189]
That is, future medical application of elastase depends upon the development of means to increase the amount of elastase to be absorbed through intestine.
With this in mind, the inventors have made intensive investigations and, as a result, have found that addition of sucrose fatty acid ester remarkably increases absorption of elastase, thus having achieved the present invention.